This application and its disclosure generally relate to the field of positioning human jaws for dental procedures.
As described in U.S. Pat. No. 9,579,046, a position of a human head can be unambiguously determined using the described methods of 3D geometric modeling. Once such position is determined, however, it is desirable to secure the human head in such position or at least provide a fixed point of reference, which can then be used for subsequent dental and/or other procedures. In other words, it is desirable to provide a sensor reference point on the mandible, i.e., the lower jaw.
Cervicocranium is a complex anatomical structure consisting of C2, C1 and base of the Cranium. Present art of measuring mandibular movement involve fixing a magnet on the lower central teeth and picking up the tracings with a magnetic field frame within which the magnet is moving during opening and closing movements of the jaw. When mandible translates into full range of motion during opening and closing it may involve undetectable and unmeasurable cervicocranial movements, which can cause false positive and false negative mandibular ROM results if the measurement system does not provide for such compensation. Existing systems which are currently in the market lack a compensation element for the cervicocranial movements that makes their data erroneous.
Therefore, it is desirable to provide a sensor reference point compensating for the cervicocranial movements. Such sensor reference point should possess the following: it should be located outside of the mouth; it should be inexpensive and user-friendly in application; it should be simple and predictable in positioning, it should conform with all infection control requirements; it should not move once positioned and stay without movements while the mandibular tracings are taken; it should allow sufficient time for testing; it should be easily replaceable, if necessary; and it should be comfortable to all patient situations (with, or without regard to the presence of teeth)
Other methods and systems, currently in use, utilize dual inclinometers, bubble goniometers, radiographs, compass technology, visual estimation, ultrasound, geometric methods, digital optoelectronic instruments, computerized kinematic analysis using passive markers and infrared TV cameras, MRI or sensors attached to the subject's head for head orientation determination.
However, none of the existing systems is simple enough to use nor yields sufficient accuracy in identifying a particular reference point.